/Engine/Plugins/Runtime/GeometryProcessing/Source/DynamicMesh/Public/Operations/PolyEditingUVUtil.h
Create a new single UV island for the provided TriangleSet in the given Mesh/UVOverlay, by computing an ExpMap parameterization based on an automatically-detected midpoint of the triangle patch. The UV scale is determined automatically based on the UV/3D area ratio of triangles adjacent to the TriangleSet (using a ratio of 1 if the triangles have no neighbours).
namespace UE { namespace Geometry { void UE::Geometry::ComputeArbitraryTrianglePatchUVs ( [FDynamicMesh3](API\Runtime\GeometryCore\DynamicMesh\FDynamicMesh3) & Mesh, [FDynamicMeshUVOverlay](API\Runtime\GeometryCore\DynamicMesh\FDynamicMeshUVOverlay) & UVOverlay, const [TArray](API\Runtime\Core\Containers\TArray)< int32 > & TriangleSet ) } }